Abstract: A method for operating an internal combustion engine Exhaust Gas Recirculation (EGR) system that includes producing an EGR valve position signal to decrease the amount of exhaust gas passed to the EGR cooler when a processor determines the EGR cooler efficiency is less than the predetermined level and producing an EGR coolant valve position signal to decrease the amount of coolant passed to the EGR cooler when such processor determines the EGR cooler efficiency is less than the predetermined level. The processor produced EGR valve and the EGR coolant valve position signals result in regeneration within the cooler, returning the effectiveness of the cooler to a near “clean” condition.

Abstract: While the materials compatibility challenges have largely been met in “flex-fuel” vehicles, the engine and aftertreatment operation has not been optimized as function of fuel type (i.e. ethanol, biodiesel, etc.). The full-scale introduction of alternative fuels is most likely going to occur as blends with conventional fuels. This is seen to some extend with the limited introduction of E85 (85% ethanol, 15% gasoline) and B20 (20% biodiesel, 80% conventional diesel.). This further exacerbates the challenge of accommodating variable fuel properties, as there will be differences in combustion properties due to both the type of alternative fuel (i.e. pure biodiesel vs. pure diesel) and blend ratio (i.e. B20 vs. B80). Real-time estimation of the fuel blend is key to the optimized use of two-component fuels (e.g. diesel-biodiesel, gasoline-ethanol, etc.). The approach outlined here uses knowledge of the exhaust composition, fuel and air delivery rates to the engine to estimate the fuel blend.

Abstract: An object of the present invention is to provide a fuel injection control technique which maximizes engine power according to fuel evaporation characteristics. The fuel injection timing in the intake stroke is delayed according as a physical quantity affecting the fuel evaporation time changes such that the fuel evaporation time decreases. Further, the fuel injection timing when a physical quantity affecting the fuel evaporation time is such that the fuel evaporation time decreases is set closer to the end of the intake stroke than the fuel injection timing when the physical quantity is such that the fuel evaporation time increases. The fuel injection timing is controlled so as to maximize engine power according to fuel evaporation times.

Abstract: An engine control system includes a scavenging module that generates a scavenging signal when both a driver torque request is greater than a predetermined torque threshold and a rotational speed of an engine crankshaft is less than a predetermined speed threshold. A cam phaser control module controls intake and exhaust cam phasers based on the scavenging signal such that opening times of intake and exhaust valves of a respective cylinder overlap.

Abstract: A comparator compares the total intake air amount accumulated by an accumulator with a reference value obtained via a selector. If the total intake air amount is smaller than the reference value, the CSS control is determined as being abnormal and a CSS-abnormality signal is output. If the number of times an atmospheric pressure learning value has been updated is equal to or larger than a threshold that is set large enough to determine that the accuracy of the calculated atmospheric pressure learning value is sufficiently high, a reference value is output from a characteristic storage to the comparator. Conversely, if the number of times the atmospheric pressure learning value has been updated is smaller than the threshold, an initial reference value is output from an initial reference value storage to the comparator.

Abstract: The present invention provides a cross-cycle internal combustion engine that can conduct a combustion cycle called as the cross-cycle with diesel ignition means. The diesel type cross-cycle operation consists of seven processes, which are the intake-process, the cold-compression process, the injection process, the cold-expansion process, the exhaust process, the hot-compression process, and the diesel-ignition process.

Abstract: A control system for an internal combustion engine having an exhaust gas recirculation device for recirculating a part of exhaust gases to an intake system of the engine is disclosed. An estimated exhaust gas recirculation amount is calculated using a neural network to which at least one engine operating parameter indicative of an operating condition of the engine is input. The neural network outputs an estimated value of an amount of exhaust gases recirculated by the exhaust gas recirculation device. At least one engine control parameter for controlling the engine is calculated based on the estimated exhaust gas recirculation amount.

Abstract: A method of measuring an initial hydrocarbon concentration in a canister includes opening a purge control valve thereby introducing hydrocarbons from the canister to a cylinder; calculating an amount of air introduced into the cylinder; and calculating the initial hydrocarbon concentration based on the amount of air. A method of controlling fuel injection includes measuring an initial hydrocarbon concentration in a canister by opening a purge control valve in a fuel cut-off mode; determining a driving state of a vehicle; calculating an air inflow to a cylinder according to the driving state of the vehicle; calculating a ? set-point according to the driving state of the vehicle; and calculating fuel injection amount based on the air inflow and the ? set-point. Also, a system for controlling fuel injection.

Abstract: A method for controlling a powertrain includes selectively initiating an ammonia generation cycle, including injecting fuel into a combustion chamber of an engine before a primary combustion event to a calibrated air fuel ratio in a range lean of stoichiometry based upon generation of NOx within the combustion chamber, injecting fuel into the combustion chamber after the primary combustion event based upon an overall air fuel ratio in a range rich of stoichiometry and resulting generation of molecular hydrogen, and utilizing a catalyst device between the engine and a selective catalytic reduction device to produce ammonia.

Abstract: A system includes a hydrogen fueled internal combustion engine, a fuel system configured to provide a flow of hydrogen fuel to the engine, and an exhaust gas recirculation (EGR) system configured to provide a flow of recirculated gas to the engine which includes exhaust gases. The system also includes an engine controller configured to control the fuel system and the EGR system, such that the engine receives a mixture which includes the hydrogen fuel, the ambient air and the recirculated gas in a stoichiometric fuel/air ratio that meets the torque demand on the engine. A method includes the steps of providing a flow of gaseous hydrogen fuel, a flow of ambient air, and a flow of recirculated exhaust gas to the engine.

Abstract: The invention relates to a system for controlling the operation of a diesel engine of a motor vehicle, associated with means for supplying the cylinders with fuel and with means for recirculating waste gases at the admission. The control system comprises means for controlling the supply means according to the rotation speed of the engine and an effective torque control point and means for controlling the recirculating means according to the at least one effective torque control point. The system comprises means for determining a torque control point which is reconstructed from information provided by means for acquisition of the richness of the waste gas of the engine and air supply at the admission thereof and means for adjusting the means for controlling the recirculating means according to the effective torque control point and the reconstructed torque control point in order to minimize the emission of pollutants by the engine.

Abstract: A fuel injection controller for an internal combustion engine. The engine includes a fuel vapor treatment device having a collector for collecting fuel vapor generating in a fuel tank; a purge line that introduces purge gas into an intake passage of the engine, the purge gas being a mixture of fuel vapor released from the collector and air; and a purge valve provided in the purge line to adjust flow rate of the purge gas. The fuel injection controller corrects an amount of fuel injected from an fuel injection valve based on an amount of fuel vapor contained in the purge gas flowing into a combustion chamber of the engine. The fuel injection controller comprises an estimation section for estimating the inflow amount of the purge gas flowing into the combustion chamber based on a passed amount of purge gas that has passed through the purge valve and a compensation value for compensating transportation delay.

Abstract: A tank ventilating valve is disposed in a regeneration pipe which connects a storage container collecting fuel gas of a fuel tank to an intake pipe of the internal combustion engine. The tank ventilation system is air tightly sealed towards the atmosphere prevailing outside the motor vehicle while the tank ventilating valve is opened to create a negative pressure in the tank ventilation system. The method has the following steps: determining the fuel gas charge of the storage container; determining the volume flow rate through the tank ventilating valve; calculating an intermediate value from the product of the load and the volume flow rate; determining a tank pressure difference between the pressure prevailing in the fuel tank and the atmospheric pressure; and determining the additive corrective value by adjusting the intermediate value to the amount of the tank pressure difference.

Abstract: A gas vapor control system may include a canister for capturing gas vapor that is generated from a fuel, a throttle valve that is disposed substantially in the middle of an intake passage through which air flows into a cylinder of the engine, a gas passage that communicates from the canister to one side downstream of the throttle valve, a purge control valve that is disposed on the gas passage, and a control portion that stops an engine in an idle state and controls a real fuel injection amount that is to be injected while restarting the engine according to a first fuel amount that is included in gas vapor that is discharged into the intake passage.

Abstract: There is described a method for determination of an application time for a tank ventilation on an internal combustion engine. An excessive enrichment of the air/fuel mixture can be avoided by means of a timely application of injection correction as result of the tank ventilation. According to said method, a threshold value comparison is carried out for a modified lambda control deviation, made up of the lambda control deviation and a pseudo lambda control deviation, whereby the pseudo lambda control deviation depends on the deviation of the lambda values from a given lambda set value.

Abstract: Described herein are various embodiments of an apparatus, system and method for operating a dual fueled spark ignition engine. For example, according to one illustrative embodiment, a method for operating a dual fueled spark ignition engine includes fueling the engine solely with a combustion promoter within a first engine load range between zero and an engine load associated with a target combustion condition selected from the group consisting of rough limit, knock limit, and any of various conditions between the rough limit and knock limit. Within the first engine load range, the amount of combustion promoter fueling the engine increases as the load increases. The method further includes fueling the engine on a mixture of ammonia and the combustion promoter within a second engine load range between the engine load associated with the selected target combustion condition and the engine load associated with a maximum operating pressure of the engine.

Abstract: This in particular involves testing the operation of a fuel vapor purge valve (31). The engine (1) is running at idle. An idle speed controller (ISC, 47) acts on the engine idle speed. At a given moment in this operation of the engine, a command to open the purge valve (31) is issued and the idle speed controller is also operated in such a way that it acts on this speed to keep it substantially constant in spite of the fact that the purge valve is open.

Abstract: A fuel supply assembly is provided that may allow for use of vaporized fuel to power an engine and enhance fuel efficiency. The fuel supply assembly may include a vaporizing tank, a heating source, a temperature control and a monitoring and control system configured to control intermixing of ambient air and vaporized gasoline to maintain a desired hydrocarbon level in an exhaust.

Abstract: A fuel vapor treatment system includes a canister containing an adsorbent, a detector detecting a concentration of a fuel vapor, a purge passage for introducing the mixture gas into an engine, and an ECU which controls a purge based on a detected fuel vapor condition quantity and learns a fuel vapor concentration. If a difference between a learned concentration and a detection concentration is not less than a specified value, the ECU performs a purge control based on the learned concentration prior to a purge control based on the detection concentration.

Abstract: A CPU measures an actual air-fuel ratio based on the signals detected by the air-fuel ratio sensor. When the difference between the actual air-fuel ratio and a target air-fuel ratio is larger than a predetermined value, the computer determines that a fuel vapor amount purged into the intake passage deviates from a target value due to an incorrectness of a reference flow quantity of the purge valve. The computer calculates an actual reference flow quantity based on a measured actual air-fuel ratio, and rewrites the reference flow quantity corresponding to a current intake pressure into the calculated the reference flow quantity. Thereby, the difference between the actual air-fuel ratio and the target air-fuel ratio can be reduced.

Abstract: A control system for an internal combustion engine, which can determine just enough amounts of demanded combustion fuel and auxiliary fuel during execution of auxiliary fuel supply, for improvement of fuel economy and drivability and the emission-reducing capability of a catalyst. The control system carries out auxiliary fuel supply for a cylinder during a predetermined time period within the expansion and exhaust strokes, to control the catalyst to a predetermined state for its emission-reducing capability. The control system calculates a whole demanded fuel amount to make oxygen concentration in exhaust gases equal to a predetermined value for controlling the catalyst to the state during auxiliary fuel supply, determines the amount of demanded combustion fuel to be supplied to obtain engine output, and determines the auxiliary fuel amount based on the difference between the whole demanded fuel amount and the demanded combustion fuel amount.

Abstract: A method of controlling an internal combustion engine having a fuel vapor purging system and a fuel delivery system including a fuel pump and a fuel pressure sensor for detecting the fuel pressure provided by the fuel pump is disclosed. In one example, the method includes, during a degraded condition of the fuel pressure sensor, adjusting the fuel pump output in response to an operating condition, adjusting at least one of a condition of the fuel vapor purging system and adaptive learning of a characteristic of the fuel delivery system; and further adjusting the fuel pump output in response to an output of an exhaust gas sensor while also adjusting an amount of fuel injected into a cylinder of the engine in response to said output of the exhaust gas sensor.

Abstract: In an evaporated fuel treatment system, a pump is operated to flow air through a specified restriction and a sensor detects a first differential pressure across the restriction. A fuel tank, a canister, and the restriction are made to communicate with each other and an air-fuel mixture containing the evaporated fuel is purged from the canister. The mixture flows through the restriction and a second differential pressure across the restriction is detected. A differential pressure ratio and an evaporated fuel concentration used for the control of a flow rate are computed from these differential pressures. When fuel swings in a period during which the second differential pressure is detected, the pressure difference ratio is not computed and the flowrate control of the air-fuel mixture is not conducted.

Abstract: Operation of an internal combustion engine with oil lubrication and electronic fuel injection, includes the steps of determining a flow of fuel mass (mkp_ausg) evaporating out of oil, and determining a setpoint injected-fuel quantity (rk_ev) with taking into account the determined flow of fuel mass.

Abstract: A feedback correction coeficient used to perform feedback-control of the fuel injection amount based on the air-fuel ratio of exhaust gas is calculated. A concentration updating based value is set based on the deviation of the oscillation center of the feedback correction coefficiect, and a vapor concentration correction coefficient corresponding to the fuel concentration of purge gas is updated using the concentration updating base value. During the period where the fuel concentration of purge gas is expected to sharply decrease, the concentration updating base value is increased.

Abstract: A method and a system for improved control of fuel supply to an internal combustion engine are presented. The system, in addition to a liquid fuel injector, includes a fuel vapor injector disposed in an engine air intake manifold. The method includes determining the state of fuel in the liquid fuel line, and adjusting the amount purge fuel vapors injected into engine air intake manifold accordingly. Thus, improved engine performance is achieved.

Abstract: A fuel vapor treatment apparatus includes a first determiner that determines a concentration of purged fuel based on an amount of deviation from a target air-fuel ratio of an air-fuel ratio detected by a sensor provided in an exhaust pipe. A second determiner that determines the concentration of purged fuel in a state in which a purge control valve is closed. Air-fuel ratio controller controls a fuel injection quantity to bring an air-fuel ratio to the target air-fuel ratio on the basis of the concentration of the purged fuel. The air-fuel ratio controller uses the concentration of fuel determined by the second determiner when purge is started or restarted, and uses the concentration of fuel determined by the first determiner thereafter in the course of performing purge. It is possible to increase a purge ratio when purge is started or restarted.

Abstract: A method for calculating transient fuel wall wetting characteristics of an operating engine is described. The method accounts for cylinder valve deactivation of cylinders in the engine in calculating the dynamic fueling compensation. In one example, fuel vaporization effects from fuel puddles in deactivated cylinders are considered when calculating the fueling compensation for active cylinders.

Abstract: The invention is intended to provide improved emission-cleaning performance by use of a three-way catalyst alone, without the need for a lean NOx catalyst, while ensuring a fuel economy improvement effect of lean burn operation. A multicylinder spark-ignition engine is constructed such that, in a pair of preceding and following cylinders whose exhaust and intake strokes overlap each other, burned gas discharged from the preceding cylinder (2A, 2D) which is currently in the exhaust stroke is introduced directly into the following cylinder (2B, 2C) which is currently in the intake stroke through an intercylinder gas channel (22) and gas discharged from only the following cylinder (2B, 2C) is led to an exhaust passage (20) provided with a three-way catalyst (24) in a low-load, low-speed operating range.

Abstract: A control apparatus for an internal combustion engine prevents variation of an air fuel ratio even upon introduction of purge air. A delay time occurring until the intake air detected, after having arrived at the combustion chamber through a surge tank, influences an air fuel ratio sensor, a delay time occurring until purge air containing evaporated fuel generated upon purging a canister, after having arrived at the combustion chamber through the surge tank, influences the air fuel ratio sensor, and a delay time occurring until fuel supplied by an injector, after having arrived at the combustion chamber, influences the air fuel ratio sensor, are represented by simplified physical models. A purge rate in the combustion chamber or in the neighborhood of the air fuel ratio sensor is calculated by using the physical models, and a purge air concentration and a fuel correction amount are calculated based on the purge rate thus obtained.

Abstract: If the amount of fuel added to exhaust gas becomes excessive as a result of an abnormality of an addition agent supply unit (60), the air-fuel ratio of exhaust as decreases. If an exhaust gas air-fuel ratio obtained from a value output from an A/F sensor (4) remains equal to or smaller than a predetermined value for a predetermined period, an ECU (2) determines that an addition agent supply unit (60) is abnormal. Upon detection of an abnormality of the addition agent supply unit (60), the ECU (2) incrteases an amount of EGR gas recirculated to the intake side by an EGR unit (40), reduces an amount of fuel injection from injectors (11), and restricts an operational state of an engine body (10) to a low-speed/low-load state. Also, the ECU (2) turns a warning lamp (7) on, warns a driver of the abnormality of the addition agent supply unit (60), and makes it possible to pull a vehicle over safely.

Abstract: A system for controlling the air-to-fuel ratio in an internal combustion engine includes an air intake conduit coupled to an intake manifold, an EGR valve disposed in-line with an EGR conduit responsive to a valve control signal, a lambda sensor producing a lambda signal indicative of the air-to-fuel ratio of the exhaust gas and a control circuit producing the valve control signal as a function of a desired mass air flow value, a desired air-to-fuel ratio, and the lambda signal. In an alternate embodiment, the system further includes a fueling system responsive to a fueling control signal. In this embodiment, the control circuit produces the fueling control signal as a function of a desired fuel control value, a desired air-to-fuel ratio, and the lambda signal. In another alternate embodiment, the control circuit produces the valve control signal as a function of a desired air-to-fuel ratio and the lambda signal.

Abstract: A method and a device are described for controlling an internal combustion engine. On the basis of the comparison of a setpoint value with an actual value for a variable that characterizes the supplied oxygen quantity, an actuating variable is predefined for controlling an actuating element that influences the fuel quantity conducted to the internal combustion engine and/or the oxygen quantity supplied to the internal combustion engine. The actual value and/or the setpoint value are/is normalized to a reference value.

Abstract: A method for calculating transient fuel wall wetting characteristics of an operating engine is described. The method accounts for cylinder valve deactivation of cylinders in the engine in calculating the dynamic fueling compensation. In one example, fuel vaporization effects from fuel puddles in deactivated cylinders is considered when calculating the fueling compensation for active cylinders.

Abstract: A control apparatus is provided for a sealed fuel tank system which is applied to an engine including a throttle valve provided in an intake pipe, and which includes a vaporized fuel supply pipe that connects a fuel tank and the intake pipe, and a control valve that opens and closes the vaporized fuel supply pipe. The control apparatus includes a controller which maintains the control valve in an open state on the condition that a pressure in the fuel tank is equal to or higher than a reference determination pressure; and corrects an opening amount of the throttle valve to a value equal to a first control opening amount that is smaller than a required opening amount set based on an operating state of the engine by a first correction opening amount when the control valve is in the open state.

Abstract: Various systems and methods are disclosed for carrying out combustion in a fuel-cut operation in some or all of the engine cylinders of a vehicle. Further, various subsystems are considered, such as fuel vapor purging, air-fuel ratio control, engine torque control, catalyst design, and exhaust system design.

Abstract: The present invention judges whether an internal combustion engine is operated by a special operation method in which a fuel cut is performed more frequently than predefined depending on the operation of an accelerator pedal. The present invention provides a shorter purge resumption period subsequently to recovery from a fuel cut when it is judged that the internal combustion engine is operated by the special operation method than when it is judged that the internal combustion engine is not operated by the special operation method. The purge resumption period is a period during which a purge gas flow rate is lower than during a steady operation.

Abstract: A system is described using a fuel quality sensor or an estimate of fuel volatility for controlling various aspects of engine operation. For example, improved fuel tank leak detection may be achieved using an estimate of fuel volatility obtained from fuel purging operation.

Abstract: Operating method and apparatus for operating an engine controller for an internal combustion engine, including operating in a first operating mode, acquiring at least one state variable (CL, Adap_Fenst_fac, Adap_Fenst_Add) of the internal combustion engine and changing over from the first operating mode into a second operating mode. The changeover from the first operating mode into the second operating mode take place as a function of the determined state variable (CL, Adap_Fenst_fac, Adap_Fenst_Add) of the internal combustion engine.

Abstract: There is described a method of controlling injection in a vehicle internal combustion engine, wherein the intake air flow and exhaust lambda are measured to estimate the fuel quantity actually injected into the engine and perform a closed-loop control whereby the estimated fuel quantity is made to substantially equal the nominal fuel quantity calculated to meet vehicle user requirements. More specifically, the difference between the nominal fuel quantity and the estimated fuel quantity is used to calculate a correction factor by which to correct the nominal fuel quantity.

Abstract: When fuel vapor flows to an intake passage from a canister, the amount of fuel injected to an internal combustion engine is corrected to suppress fluctuation of the air-fuel ratio in the engine due to the fuel vapor. An EGR mechanism variably sets the EGR rate. When the pressure in a fuel tank is greater than or equal to a predetermined value, a tank sealing system releases gas containing fuel vapor from the fuel tank to the canister on condition that fuel vapor is flowing to the intake passage from the canister. A controller controls the EGR mechanism to reduce the EGR rate when gas is released from the fuel tank to the canister. Therefore, combustion is stabilized even if EGR is executed when gas in the fuel tank is released.

Abstract: A combustion variation value is detected, and a function that uses the detected combustion variation value is added to CVAR(i?1) to obtain CVAR(i); and using the resulting value, an exhaust gas recirculation amount and an ignition timing are obtained. A combustion variation is detected, and if the detected combustion variation value is equal to or greater than a predetermined value, the value of flag is set to be 1, and the exhaust gas recirculation amount and the ignition timing are reset to previous values. If the detected combustion variation value is less than the predetermined value, the value of the flag is set to be zero, and a current combustion variation manipulation correcting amount CVAR(i) is updated. If the value of flag is 1, the process is immediately terminated.

Abstract: A controller for an engine including a fuel vapor processing mechanism. The controller determines the amount of fuel vapor drawn into an intake passage based on the concentration of fuel vapor purged into the purge passage. The controller corrects the fuel injection amount of a fuel injection valve in accordance with the determined amount of fuel vapor. The controller starts correcting the fuel injection amount from the cylinder that is undergoing an intake stroke when the crankshaft is rotated to a certain crank angle.

Abstract: An internal combustion engine adapted for combustion of stoichiometric and non-stoichiometric air/fuel mixtures includes an intake system, a combustion chamber which is adapted for direct injection of a fuel and an exhaust system. The intake port flow output comprises an intake airflow output and an EGR airflow output. An intake port flow estimator determines an intake port gas flow output from the intake mass airflow input of the intake airflow into the intake manifold and the EGR mass airflow input of the EGR airflow of the EGR airflow into the intake manifold using a plurality of engine parameters and an air/fuel adjustment factor. The intake port gas flow output is determined as an effective intake airflow output and an effective EGR airflow output. The effective intake airflow output to the combustion chamber is used to determine an effective mass of intake air output per cylinder.

Abstract: Various systems and methods are disclosed for carrying out combustion in a fuel-cut operation in some or all of the engine cylinders of a vehicle. Further, various subsystems are considered, such as fuel vapor purging, air-fuel ratio control, engine torque control, catalyst design, and exhaust system design.

Abstract: A system for controlling fuel injection in an engine. The engine includes an intake passage, an intake passage injector, a cylinder having a combustion chamber, and a cylinder injector for injecting a target amount of fuel into the combustion chamber. The system includes a controller for controlling the intake passage and cylinder injectors to permit fuel injection, each with an injection ratio, while said engine operates in a condition in which said engine permits fuel injection from said cylinder injector, a sensor for sensing the amount of fuel injected from the cylinder injector, a detector for detecting the difference between the target injection amount and the amount of fuel injected and an adjuster for adjusting the injection ratio based on the result of the detection by the detector so that the intake passage injector performs fuel injection together with the fuel injection performed by the cylinder injector.

Abstract: An electronic valve actuation system and control method is described. The valve timing is changed between early and late intake valve closing depending on engine operating conditions. Further, valve timing is adjusted to control engine airflow or engine torque. Finally, air-fuel ratio is adjusted based on feedback from an exhaust gas oxygen sensor as well as an estimate of air, fuel, and residual exhausted from cylinders operating with late valve closing (after bottom dead center) timing.

Abstract: An evaporative emission control system includes a canister for collecting fuel vapor from a fuel tank, and a purge control valve disposed between the canister and the intake passage of the engine. A controller of the system determines a failure of the purge control valve, executes a purging process by opening the purge control valve, executes a learning process for learning the fuel concentration of the purge gas, and executes a correcting process for correcting the amount of fuel injected into the engine based on the learned value of the fuel concentration. When the purge control valve is normal and conditions for execution of purge control are satisfied, the controller requests execution of the purging process, learning process and the correcting process. When an open failure occurs in the purge control valve, the controller always requests execution of the learning process and the correcting process.

Abstract: A vehicle control system regulates oxides of nitrogen levels in vehicle emissions. Recirculation of exhaust gas in an engine is controlled with an exhaust gas regulator valve and/or a cam phaser. An oxides of nitrogen sensor determines the level of oxides of nitrogen levels in the exhaust gas and communicates the information to a vehicle controller. The controller determines if the oxides of nitrogen levels are within a predetermined threshold according to a lookup table. The controller adjusts the valve and/or cam phaser if the oxides of nitrogen levels are not within the threshold.

Abstract: Air-fuel ratio control apparatus for an engine of automobile for controlling an air-fuel ratio to a desired value includes module (33) for computing a purge ratio (Pr) from a purge quantity (QPRG) and an engine operation state, module (35) for computing a purge air concentration (Pn) from the purge ratio (Pr) and an air-fuel ratio feedback correcting coefficient (CFB), module (36) for computing a purge air concentration correcting coefficient (CPRG) from the purge ratio and the purge air concentration, module (39) for computing a fuel injection quantity (Qf) supplied to the engine (6) from the purge air concentration correcting coefficient, and module (37) for detecting an accelerating state of the automobile. The purge air concentration correcting coefficient is reset to an initial value when the purge air concentration correcting coefficient is not greater than a predetermined value (indicating leanness) and when the acceleration is detected.